1. Field of the Invention
The present invention relates generally to torque converters for automatic transmissions and, more particularly, to a method for diagnosing a lock-up mechanism for a torque converter in an automatic transmission of an automotive vehicle.
2. Description of the Related Art
Torque converters are used in automatic transmissions for automotive vehicles to transfer power from a prime mover such as an engine of the automotive vehicle to a change speed gear box of the transmission from where it is transmitted to a drive unit such as a final wheel drive of the vehicle. These torque converters typically include a lock-up clutch or mechanism to mechanically interconnect an impeller and turbine of the torque converter during certain operating conditions.
An example of a lock-up mechanism for a torque converter in an automatic transmission is disclosed in U.S. Pat. No. 4,289,048 to Mikel et al. Although this lock-up mechanism has worked well, there is no provision for detecting a malfunction of the torque converter based on proper unlock and lock of the lock-up mechanism. Therefore, there is a need in the art to provide a method for diagnosing a torque converter's lock-up mechanism for detecting a malfunction of the torque converter.